Number Density is a term for the number of objects per unit volume. N n = — V for Number Density n, number of objects, N and volume V. The term is often used for atoms or molecules, e.g., in a gas, in contrast to other measures such as Mass Density. Number Density can also be used for larger objects, e.g., stars. Referenced by: Absorption Coefficient Boltzmann Equation Column Density Luminosity Function (LF) Saha Equation |